A convertible bond falls under the category of debt security. It is also known as a hybrid security. A convertible bond has the exposure of both debt and equity.
Convertible bonds are quite known for its feature of converting the number of stocks shares at certain points of the bond’s life. This bond is with stock options.
The expectation of returns through this bond is low.

Convertible Bondholder receive fixed returns regardless profit result of the company.
If the company earns well, bondholder gets his share from operating income.
Bondholder can trade the bond with equity. They have the scope to achieve high dividends provided the company's profitable status.
Bondholder can encash the bond at the maturity date.
The value of the convertible bond has a limitation to fall below the price at which the yield would be on par with that of a nonconvertible bond of the same period.

Concluding all of the above, I would say the ultimate truth of investment, that No investment is 100% risk-proof. Thus, convertible bonds have their own risk in investment.